Contents
Contributor contact details ix
Woodhead Publishing Series in Textiles xi
1 Introduction to composite nonwovens 1
D. DAS, Indian Institute of Technology Delhi, India
1.1 Introduction 1
1.2 Classifi cation of composite nonwovens 5
1.3 Processing, markets and applications 13
1.4 Conclusion and future trends 15
1.5 Sources of further information and advice 16
1.6 References 16
2 Natural and synthetic fi bres for composite nonwovens 20
S. MUKHOPADHYAY, Indian Institute of Technology Delhi, India
2.1 Introduction 20
2.2 Natural and biodegradable fi bres for nonwovens 20
2.3 Polypropylene and polyester fi bres 22
2.4 Polyethylene and nylon fi bres 23
2.5 Bicomponent fi bres 24
2.6 References 28
3 Structure of composite nonwovens 30
D. DAS, Indian Institute of Technology Delhi, India and
B. NECKÁŘ, Technical University of Liberec, Czech Republic
3.1 Introduction 30
3.2 Fibre characteristics in composite nonwovens 30
3.3 Fibre packing in composite nonwovens 41
3.4 Fibre orientation in composite nonwovens 44
3.5 Pore characteristics in composite nonwovens 52
3.6 Conclusion 56
3.7 Sources of further information and advice 56
3.8 References 57
4 Properties of composite nonwovens 58
D. DAS, Indian Institute of Technology Delhi, India
4.1 Introduction 58
4.2 Mechanical properties of composite nonwovens 58
4.3 Fluid permeability of composite nonwovens 60
4.4 Thermal properties of composite nonwovens 64
4.5 Liquid sorption characteristics of composite nonwovens 65
4.6 Particle fi ltration behaviour of composite nonwovens 66
4.7 Conclusion 71
4.8 Sources of further information and advice 71
4.9 References 71
5 Composite nonwovens in absorbent hygiene products 74
D. DAS, Indian Institute of Technology Delhi, India
5.1 Introduction 74
5.2 Key material requirements 75
5.3 Baby diapers 76
5.4 Feminine sanitary pads 81
5.5 Adult incontinence pads 84
5.6 Conclusion and future trends 86
5.7 Sources of further information and advice 87
5.8 References 87
6 Composite nonwovens in wipes 89
R. S. RENGASAMY, Indian Institute of Technology Delhi, India
6.1 Introduction 89
6.2 Materials in wipes 90
6.3 Wet wipes 91
6.4 Web forming technologies for wipes 92
6.5 Web bonding processes for wipes 95
6.6 Surface texturing of wipes 96
6.7 Composite nonwoven wipes 97
6.8 Multi- fi bre composite nonwoven wipes 98
6.9 Multilayer composite latex bonded nonwoven wipes 100
6.10 Hydroentangled (spunlaced) multilayer composite nonwoven wipes 100
6.11 Thermobonded multilayer composite nonwoven wipes 109
6.12 Needlepunched composite nonwoven wipes 112
6.13 Other multilayer nonwoven wipes 113
6.14 Conclusion and future trends 113
6.15 References 118
7 Composite nonwovens in fi lters: theory 120
A. MUKHOPADHYAY, National Institute of Technology Jalandhar, India
7.1 Introduction 120
7.2 Mechanisms of fi ltration: general 125
7.3 Mechanisms of fi ltration: particle capture entrapment 126
7.4 Adsorption 140
7.5 Absorption 141
7.6 Coalescing 141
7.7 Media for gel removal 144
7.8 Mechanisms of fi ltration: electro- fi ltration 146
7.9 Separation by antimicrobial media 147
7.10 Extraction 147
7.11 Key requirements for fi ltration media 147
7.12 Characteristics of nonwoven fi lters 151
7.13 Types of nonwoven fi lter 152
7.14 Conclusion 160
7.15 References 161
8 Composite nonwovens in fi lters: applications 164
A. MUKHOPADHYAY, National Institute of Technology Jalandhar, India
8.1 Introduction 164
8.2 The role of composite nonwovens in fi lters: combining
mechanical support and durability with fi ltration 166
8.3 The role of composite nonwovens in fi lters: providing two
or more layers of different fi ltration effi ciency 181
8.4 The role of composite nonwovens in fi lters: combining
different separation technologies/functionality into one filter medium 182
8.5 Applications of composite nonwovens 190
8.6 Applications in air/gas fi ltration 192
8.7 Applications in liquid fi ltration 198
8.8 Applications in engine fi ltration 200
8.9 Conclusion 204
8.10 References 204
9 Composite nonwovens in medical applications 211
S. GHOSH, Indian Institute of Technology Delhi, India
9.1 Introduction 211
9.2 Surgical gowns 212
9.3 Surgical facemasks and other clinical wearable products 213
9.4 Wipes 214
9.5 Wound dressings, pads and swabs 214
9.6 Scaffolds for tissue engineering 216
9.7 Hernia meshes 218
9.8 Filtration materials for medical applications 219
9.9 Incontinence products 220
9.10 Conclusion and future trends 220
9.11 References 220
9.12 Appendix: recent patents based on composite nonwovens
for medical applications 223
Index 225